The invention relates to a vacuum producing device comprising at least one ejector device, having a jet nozzle with a receiving nozzle placed downstream from it and furthermore with a draw off zone defined in the transition zone between the jet nozzle and the receiving nozzle, a receiving space being present at the outlet end of the receiving nozzle, said receiving space serving for the fluid flowing through the receiving nozzle, an exit flow duct leading off from the said space, and furthermore means for influencing the fluid flow through the exit flow duct.